Still thinking about this...
On one hand, some people are more attractive than others, and even if you love someone, you may not find them as "beautiful" or physically attractive as many others. Also, would it have been better if he'd lied and said you were more attractive (to him)? It would've been a lie, and you'd have known that.
On the other hand, he could've been much more tactful in his answer, and he really shouldn't be so tacky as to be talking about this, anyway (and he's even more of an idiot to do it in front of you).
Final verdict, he's gross for rating women this way, and at the very least I'd tell him I didn't want to hear another "rating" out of his mouth ever again. (Even apart from everything else, who really cares how he ranks attractiveness? Why would anyone want to know who/what he finds appealing?)
I suspect that the kind of man who does this is probably a jerk or less than satisfactory in other ways, as well. It might not be a bad idea to take a step back and re-evaluate the relationship.